As was just brought up in the discussion about the vote, the current markdown-parsing in the comments is causing quite a few bugs and the associated convenience might not be worth the costs of the bugs. We now have an experimental option in your user-profile to switch to a pure markdown editor, so it might make sense to just remove the automatic markdown parsing from the comment editor and have it just be a pure rich-text editor.
I left two comments that you can vote on to decide between the options.
Personally I prefer having no visible buttons, it makes the interface cleaner and more elegant.
Maybe make this an option as well?